Sorry I didn't get this part:
"5. leecher: accept invitation = quest reset
6. killer: exit game (before the leecher joins the game)
7. leecher: exit game = group will shut down (exit before it starts to switch to other game)
8. leecher: start a new game and... BANG BOOM BBBOOOOIIIIING"

What quest reset?
"Switch to other game" - wtf is this? :P
What doing after 8.?
start new game and BANG BOOM BBOOIIING?? wtf is that